Western Australian voters will return to the polls after the High Court declared the WA Senate result from last year's federal election void.
The decision to void the election result means a new Senate poll will be held. This is expected to be in May.
"The only relief appropriate is for the election to be declared void"Justice Kenneth Hayne
The Australian Electoral Commission had petitioned the court for these results to be declared void after 1,370 votes were lost during a recount.
High Court had earlier ruled on Tuesday that two candidates were not duly elected during last year's federal election but could not say who was elected in their place due to the missing votes.
Justice Kenneth Hayne declared that because 1370 ballots disappeared between the vote and recount those voters were effectively "prevented from voting".
It is believed that some of the missing ballot papers were from the Bunbury East booth in Forrest.
Justice Hayne said the court could not determine who was elected by comparing results from the count and recount.
"It is neither relevant not necessary to undertake that consideration because the court must find that Mr Dropulich and Senator Ludham were not duly elected, but cannot declare who was elected," Justice Hayne said.
"The only relief appropriate is for the election to be declared void," he said in his judgment.
The Labor Party and the Palmer United Party (PUP) both made submissions that the 2013 result should be upheld, but these were dismissed.
There will be no restrictions on new candidates or parties nominating for the Senate re-election. They don't have to have contested last year's election.